Centrifugal sand-mixing machine



Feb. 17. 1925.

A. A. WICKLAND CENTRIFUGAL SAND MIXING MACHINE 3 Sheets-Sheet 1 Filed July 14, 1921 INVENTO/E A21 4 0- WM W/ T/VESSES/ Feb. 17. 1925.

. 1,526,618 A. A. WICKLAND CENTHIFUGAL SAND MIXING MACHINE Fil y 14, 1921 3 Sheets-Sheet 2 //v vsN r012 Feb. 17. 1925.

A. A. WICKLAND CENTRIFUGAL SAND MIXING MACHINE Filed July 14, 1921' 3 Sheets-Sheet 3 //v VEN 7'01? W Q MM Patented Feb 17, 1925.

ALGOT a. virircnnann, on onrcneo, ILLINOIS.

CEN'IRIFUG-AL SAND-T/IIXING llilACI-IINE.

Application filed July 14,

To all whom it may concern:

Be it known that I, ALoo-r A. ll roninnn a citizen of the United States, and resident of Chicago, in the county of Cook and State of Illinois have invented certain new and useful Improvements in Centrifugal Fland- MiX-ing Machines; and I do hereby declare the following to be a full, clear. and exact description "of the invent-ion such as will enable others skilled in-the art to which it appertains, to makeand use the same, reference being had to the accompanying drawings, which form a part of this specification.

My invention pertains-to a new and useful centrifugal sand mixing machine and it has for its object, to provide a mechanical means for efficient rmixing, kneading and conditioningof foundry sands.

A further object of iny invention is to provide adev ice of simple mechanical con struction in which all partssubiected to wear and abrasion are accessible and may bereadily inspected, adjusted or replaced.

A: further object of my invention is to provide effective meansfor the removal of the fine dust particles contained in used molding sand and also to cool and aerate the sand, leaving it in perfect condition for re-use The invention comprises further objects and novel features which will be hereinafter fully described and illustrated in the accompanyin;- drawings wherein is shown the pre ferred embodiment of the invention, but it is understood that modifications can be made which come within the claims here- 1 unto appended.

To obtain a full and correct understanding of the details of construction, combination of features, elements and advantages, reference is to be had to the accompanying drawings.

Figure l is a cross sectional view showing the stationary framing and revolving elements. Figure 2 is a plan view on line (ls-(r, showing the cylindrical frame and cover plate also brackets for supporting driving mechanism. Figure 3 is a bottom view of'disc 4-. Figure 4: is a plan view of the revolving elements, perforated segments, and also the stationary shell or main frame on line IF-b; Figure 5 is a front view of 1921. Eerial No. 484,544.

segments on line (a, (Z. Figure 6 is a sectional view of the motor support and thrust hearing. Sim lar characters indicate corresponding; parts in the several views.

By referring to Figure 1 it will be seen that the main frame 1 of the machine con sists of a circular shell having three or more vertical legs and a center spider for support:- ing' the lower shaft bearing 12. ll'lounted on this frame 1. is a circular head which is hollow said head provided with openings 15 communicating with the interior of the shell and overlapping the inner wall of frame 1. This head is also provided with a ange and integral web to support the sectional cover plate 3 and the segments 6. The interior hollow section of the circular head 2 terminates in a tangential opening 16 which may be connected to an exhaust stack or exhauster, not shown on the draw ing.

The removable sectional disc 3 serves to cover a revolving disc 4:, and guides or confines the flow of material fed into the ma chine to the center or rotational axis of the disc, as shown in Fig. :2. Disc 4- is keyed to the driving shaft 9. A plurality of loosely fitting- Muller rings 5 are arranged to operate in conjunction with disc 4:. These rings are losely mounted on axially arranged pins 8, carried by disc at, and are held in place by a retainer ring" 7, arranged thereabove, and which in turn is keyed to the pins 8 to prevent an axial movement of the rings. The hlullcr rings are free to o slidably move radially of the disc i, but they are limited in their outward radial movement by engagement with the driving pins 8. t will be noted that the rings 5 can never directly engage with the adjacent face of the segmental ring; 6, and in practice the nearest they reach this ring is about A plurality of radially adjustable, perforated segments 6 form a complete circle or enclosure around the periphery of the revolving elements. This enclosure forms a track, spaced from and presenting a grating or perforated surface to the lilullerring the track surface being shown most clearly in Fig. 5. This track consists of theseveral segments 6 which are securely bolted to the under face of the head casting 2, and pro,

' sua ortin the removable cover )late 0.

IJI

vision is made so that these segments may be moved readily inwardly to compensate for wear between the track or working surfaces of the segments 6 and the Muller rings In Fig. 4, one of the segments is shown in section on the line ee Figure 5. It will be seen that the working faces of these segments are constructed with a number of vertical ribs 6 alternately with corresponding openings or perforations which form a continuous track orenclosure as previously mentioned. The construction of these segments may be modified in several ways as long as the object is attained of providing a circular track, consisting of alternate ribs and openings opposite to the path of the Muller rings 5. For the purpose of illustration, these segments are shown construct ed with a horizontal body flange having diagonalbraces or ribs to support the perforated face of the segment.

The recessed portion of the head 2 permits access to the bolts provided for holding the segments 6 in place. This head is also provided with a suitable flange for The circular shell 18 which is preferably an integral part of the main frame 1, serves the purpose of confining the material passing through the machine and an extension 19 may be provided thereon to guide the material into a suitable receptacle below the shell, as for instance a wheelbarrow or a conveyor belt, for final disposal.

An axial bearing with-a removable bushing was provided at the lower end of the driving shaft, this bearing being protected from dust by a circular wall and groove in parts 13 and 4.

The "disc 4i? 'has'a number of vanes on the under face, and the purpose of these vanes is to cause a sufficiently rapid circulation and radial flow of air within the machine while in operation to aerate the sand, butnot'sufiiciently rapid to produce a blast. The opposite end of the driving shaft 9 isfrun in a bearing supported by bracket 10 and a thrust. bearing'l i carries the axial load of the revolving elements This shaft 9' may be driven either by a belt and pulley or directly by an electric motor 11, as shown onFigurefl.

The nature of molding sand is such thatit will readily clog up mixing machinery, rollers, paddles, or other agitating devices. The'clay content apparently separates from the sand, and will adhere to, dry and bake on any surface with which it comes in contact, which will quickly leadto clogging of the machine parts unless this material is frequently scraped off, I

In its natural state molding sand, as commonly used" in foundr-ies,consists of a fine grade of silica sand with a mixture of organ-ic matter. and clay. The clay content is not uniform, and frequently appears as small globules. To secure the required bonding and refractory properties of molding sand, it is necessary to mix various grades of sands, and best results are obtained when this mixing is performed in a manner re sembling a kneading process. The clay particles-must be squeezed in order to be thoroughly mixed with the sharp sand. Machines performing the mixing operation by passing the sand over rolls are not suitable for the reason that the action of the crushing rolls will pulverize the sand, producing very fine, minute particles, which is veryobjectionable.

In operating this machine, the shaft 9 revolves at a-speed sufficient to cause the Muller ring 5 to move readily outwardly, due to centrifugal force. In operating, these rings do not touch the enclosure 'or track formed by the segments, as before mentioned, as any metallic contact between the moving elements and the stationary segments 6 would prove detrimental to the material being treated. The device is particularly intended for molding sand in a rather moist state, and inthis state it consists of clay and sand crystals as its principal ingredients. This sand is fed continuously through the central circular opening in the cover, plate 3, and is deposited on the exposed face of the disc 4, adjacent its rotational axisf disc 4 the sand is thrown outwardly toward the periphery, and is arrested when it comesin contact withthe track 6 to which it has a tendency to adhere slightly because the sand is moist. The Muller rings 5 travel at a much greater speedthan the radial flow of the material, and therefore the material becomes embedded between the ex posed surfaces of the segmental track and the lvfuller ring 5, causinga thorough blending, mixing, or kneading of the ingre dients of the sand, and which will squeeze the material through the perforations in the segments 6. Should large pieces of hard substances pass through the machine, these Muller rings will yield and permit such substances to drop through the annular opening between the rings and track without damage to the wear surfaces ofthe machine.

The action of the Muller rings 5 preclude the possibility of the sand material becoming crushed because these rings roll or knead the sand, and hence do not crush it to produce fine particles of dust in the sand treated, for to. do so would make such sand inferior for foundry'purposes. Due to the action of the .Muller rings 5 thesand will be kneaded or squeezed through the openings in the track, and from thenceit will fall by gravity into the shell, or hopper 19.

.As before-stated, ordinarily all foundry sands for moldingycoreniaking and facing Owing to the loading of this managers purposes used fairlymoist, and owing to the large percentage "of clay, loam or oil contained, it has a tendency to adhere to and clog the moving parts of mechanical sand mixers. The machine here described is designed to overcome thisobj'ection and permit a continuous flow of material through the machine. For certain classes of work it becomes desirable to run the sand through the machine in a dry state to remove the accumulation of fine dust particles present and for this reason means are provided for collecting and exhausting the dust. The vanes 43* on the underside of the disc 4 tend to agitate and aerate the sand as it passes through the perforations in the segments 6 and falls into the hopper 19.

The segemental track 6 and Muller rings 5 may be readily removed when worn by simply removing the split cover plate 2. which will give access to the retainer ring 7. After this is removed the Muller rings '5 and segments 6 may be adjusted or replaced without difliculty. This construc tion also allows a convenient means for frequent inspection.

Having thus fully described my invention, I claim:

1. In a sand mixing machine, a cylindrical shell, a vertical driving shaft therein, a disc mounted on said shaft, means for feeding the sand into said shell directly onto said disc, a plurality of radially movable rings, drivably connected to said disc, and independently rotatable thereon, and movable beyond the periphery thereof, and a stationary perforated track spaced from the inner surface of the shell and radially spaced from the periphery of said disc in the plane of said rings.

2. In a sand mixing machine, a shell, a vertical driving shaft therein, a disc mounted on said shaft, means for feeding sand onto said disc, a plurality of radially movable rings drivably connected to said disc, and independently rotatable thereon, and movable beyond the periphery thereof, and a stationary perforated track, substantially in the plane of said rings, and spaced beyond the disc so as to be out of engagement with said rings to form a large annular opening between the track and disc, said opening communicating directly with the hollow interior of said shell therebelow, and said rings being freely movable across said opening to adjacent, but not into engagement with said track.

3. In a sand mixing machine, a shell. a vertical drive shaft therein, a disc carried by said shaft, a perforated track spaced annularly about said disc so as to form an annular opening therebetween, means for feed ing sand onto said disc, axially arranged pins on said disc adjacent its periphery,

.Muller rings loosely mounted on said pins so as "to be freely movable radially of "the disc to cooperate with said track and squeeze the sand through the perforations thereof, and a ring connected to said pins above said Muller rings and preventing their upward movement.

1'. In a'd'evice of the kind described and in combination, a shell, a revoluble disc ar- 'anged therein, having a vertical rotational axis. an annulus spaced from the inner wall of said shell and from said disc and having a series of circumferentially spaced openings therethrough entirely about its per1phcry, axially extending pins on said disc, Muller rings loosely mounted on said pins so as to be driven therethrough, and movable radially on said disc to adjacent but not into contact with said annulus, and means for feeding the material onto said disc adjacent its rotational axis.

In a device of the kind described, and in combination, a shell adapted to have sand fed thereinto, sand-kneading means therein and to which said sand is fed and from whence it is discharged into said shell, and means in said shell below the point of dis charge of said sand from said kneading means and operated thereby for positively circulating air upwardly through said sand as it is discharged from said kneading means.

6. In a device of the kind described, and in combination, a shell, sand-kneading means therein and to which the sand is fed through the shell, a fan in said shell below said kneading means and driven thereby for positively forcing air upwardly through said sand as it discharges downwardly from said kneading means, and means operated independent of said aircirculating means for withdrawing the dust from said material simultaneously with the aerating thereof.

'7. In a centrifugal sand mixing machine comprising a shell, a driving shaft vertically arranged within said shell. movable sandkneading means arranged in said shell and operated by said driving shaft, an exhaust duct communicating with the interior of said shell above the point of discharge of said sand from said first-named means, and

means in said shell and operated by said said rings and track and so that the large name to this specification in the presence of pieces of material will engage said rings to two subscribing witnesses.

actuate the latter radially inwardly relative v to said disc to permit said large pieces to ALGOT A. VVICKLAND.

- escape between said disc and track into the Witnesses:

shell. C. B. TEETER.

In testimony whereof I have signed my A. J. HARD R; 

